Abstract

Background Physical health of people with schizophrenia is poor and
they die early from cardiovascular disease.

Aims To describe the lifestyle of people with schizophrenia through
diet, smoking habits, weight and exercise, and to report risk of coronary
heart disease (CHD).

Method Dietary habits of 102 community-dwelling people with
schizophrenia were assessed by the Scottish Health Survey Questionnaire. Also
assessed were smoking habits, physical activity, biochemical indices of
nutrition and future risk of CHD.

Results Fewer males, compared with the general population, reached
acceptable levels for consumption of fruit, vegetables, milk, potatoes and
pulses. Fewer females reached the levels for consumption of milk and potatoes.
Mean number of fruit and vegetable portions consumed per week was 16
(s.d.=14); 71 (70%) were smokers; 25 (86%) females and 50 (70%) males were
over weight or obese; 59 (59%) considered themselves physically active; 46
(53%) had a raised cholesterol: high-density lipoprotein ratio, and 64 (74%) a
low α-tocopherol: cholesterol ratio. Mean 10-year risk of CHD in males
was 10.5% (s.d.=8) and in females 7% (s.d.=6).

Conclusions The lifestyle of people with schizophrenia must give
cause for concern in relation to CHD. Care from concern in relation to
secondary care services must address physical as well as mental health.

Most people with schizophrenia live outside hospital, where they remain
among the most vulnerable members of our community. Their physical health is
often poor (Phelan et al,
2001) and they die early,
especially from cardiovascular disease
(Mortensen & Juel, 1993),
in which poor diet, physical inactivity, obesity and smoking all contribute
importantly. With regard to diet, a high intake of fruit and vegetables may
help to prevent cardiovascular disease
(Gillman, 1996). We have shown
already in a small study (McCreadie et
al, 1998) that community-dwelling people with schizophrenia,
compared with members of the general population, were making poor dietary
choices and most were overweight or obese. Another study
(Brown et al, 1999)
reported broadly similar results. In the present study we describe in more
detail the dietary habits of a much larger group, with special reference to
fruit and vegetable intake, and compare them with members of the general
population. In addition, we report their smoking habits, the physical exercise
they take, biochemical indices of nutritional status and their predicted
future risk of coronary heart disease and stroke. Patients recruited for this
study are participants in a randomised controlled trial of a dietary
intervention, namely the provision of free fruit and vegetables for a 6-month
period; this will be reported at a later date.

METHOD

Patients

Patients with a DSM–IV diagnosis of schizophrenia
(American Psychiatric Association,
1994) were recruited from those living in the community in rural
Nithsdale, south-west Scotland, and in urban Partick, west Glasgow, Scotland.
The patients approached were all those supported in their homes by mental
health care workers, including National Health Service personnel (e.g.
attendance at day hospitals, regularly supported at home by community
psychiatric nurses) and those working in the independent sector (e.g. Dumfries & Galloway Mental Health Association, Richmond Fellowship). Patients live
on their own or 2–11 in a house. The patients are encouraged to be
responsible for their own domestic chores, including shopping and cooking;
they made their own dietary choices. The patients in this study were no longer
living with family for various reasons but their position in the community had
been assessed as sufficiently precarious for them to need additional support.
A generation ago it is likely that such patients would have been in long-stay
psychiatric wards.

All patients gave written informed consent and the study was approved by
the relevant local research ethics committees.

Assessment

The patients' diet was assessed by one of two research nurses using the
food frequency section of the Scottish Health Survey questionnaire
(Scottish Executive Health Department,
1998). In this section there is, among other things, a specific
assessment of fruit and vegetable intake. The questionnaire assesses food
intake retrospectively. Smoking habits were assessed by a questionnaire
recently used in a survey of the general population in south-west Scotland
(Waldron et al,
1995). A non-fasting blood sample was taken to measure plasma
folate, glucose, vitamins C and E, carotenoids, serum total cholesterol and
high-density lipoprotein (HDL) cholesterol. Plasma folate, vitamin E and
glucose and serum lipids were measured in the biochemistry and haematology
laboratories, Dumfries & Galloway Royal Infirmary. Plasma vitamin C and
serum vitamins A and E and carotenoids were measured at the Rowett Research
Institute, Aberdeen. Also measured was body weight, height and waist
circumference. The body mass index (BMI) (weight/height2,
kg/m2) was calculated. The level of physical activity was recorded
using the Scottish Physical Activity Questionnaire
(Lowther et al,
1999). Future risk of coronary heart disease and stroke was
estimated using the Framingham assessment and associated computer program
(Hingorami & Vallance,
1999). This assessment includes such things as age, gender,
smoking status, blood pressure, left ventricular hypertrophy (assessed by
electrocardiogram), plasma glucose and serum total cholesterol and HDL
cholesterol. A psychiatrist assessed the patients' mental state using the
Positive and Negative Syndrome Scale (PANSS) for schizophrenia
(Kay et al, 1987).
The length of illness also was recorded, as was current medication.

Statistics

Differences between groups were tested by χ2, Fisher exact
or t-tests as appropriate. Associations were measured by Pearson's
correlation. Two-tailed tests were used.

RESULTS

A total of 186 patients were approached to participate in a study that was
not only descriptive but examined dietary intervention (see above). Of these
patients, 102 (54%) consented. Those who consented did not differ in gender
distribution, mean age and living arrangements from those who refused.

Social and demographic data of the 102 who entered the study are shown in
Table 1. Males were younger
than females (mean age=43 years (s.d.=12) v. 50 (s.d.= 14);
t-test, t=2.69, d.f.=100, P=0.008) and more
had never married (63/72 v. 19/30; χ2=6.39, d.f.=1,
P=0.01). Two patients (2%)
reported that they had diabetes.

As part of the intervention study (see above) about one-third of patients
were assessed by occupational therapists, who learned that all were unemployed
and the mean amount of money they had available to spend on food was £28
per week (range £15–60).

Dietary habits

A comparison of the patients' general diet with that of the general
population of Scotland was made through reference to the dietary section of
the Scottish Health Survey
1998 (Scottish Executive
Health Department, 1998). This survey describes the dietary
choices of adult males and females in terms of frequency with which certain
food groups, both healthy and unhealthy, are consumed.

The Scottish dietary targets for 2005 were outlined in the Diet Action Plan
for Scotland (Scottish Office Department
of Health, 1996) and further endorsed in the Scottish Office White
Paper on health, Towards a Healthier Scotland
(Scottish Office Department of Health,
1999). Where possible we have compared our patients' dietary
choices with the summary findings of the Scottish Health Survey data, which
most closely reflect the aspirational targets of the Diet Action Plan for
Scotland (Table 2). Fewer males
with schizophrenia than males in the general population reached acceptable
levels for the consumption of fresh fruit, vegetables, skimmed or semi-skimmed
milk, potatoes, pasta or rice, and pulses. More male patients than those in
the general population were frequently consuming breakfast cereal. Fewer
females with schizophrenia than females in the general population reached
acceptable levels for the consumption of skimmed or semi-skimmed milk,
potatoes, pasta or rice.

The mean number of portions of fruit and vegetables consumed each week was
16 (s.d.=14). This was made up of fruits (mean number of portions=7, s.d.=10),
vegetables (mean=6, s.d.=6) and fruit juice (mean=3, s.d.=7). Females ate more
vegetables than males (mean=8 (s.d.=7) v. mean=5 (s.d.=5);
t-test: t=2.58, d.f.=100, P=0.01). The Scottish
dietary targets for 2005 stipulate an increase of average fruit and vegetable
consumption to 400 grams per day, which equates with 35 portions per week.

The results presented so far have compared the patients with the general
population in Scotland. However, almost all of our patients were unemployed
and living on state benefits. The Scottish Health Survey
(Scottish Executive Health Department,
1998) does not report the dietary habits of the unemployed but
does present findings by social class. Those in social class V had the poorest
diet. We therefore compared our patients with social class V individuals.
Fewer males with schizophrenia reached acceptable levels for the consumption
of vegetables, potatoes, pasta or rice, and pulses; fewer females reached
acceptable levels for the consumption of potatoes, pasta or rice, and pulses
(Table 3).

Dietary choices of patients and of people in social class V in
Scotland

Smoking habits

Of the patients, 71 (70%) were current smokers, 14 (14%) had given up
smoking and 14 (14%) had never smoked. The mean age at starting smoking was 18
years (s.d.=6) and the mean number of cigarettes smoked daily was 27
(s.d.=14). Of those who smoked cigarettes, 38 (54%) were heavy smokers
(≥20/day) and 40 (54%) smokers wanted to give up. The mean reasons for
smoking were: ‘enjoy it’ (49%); ‘to relax’ (43%); ‘
it's a habit/addiction’ (34%). There were no significant
between-gender differences in rates of smoking or number of cigarettes smoked
per day. More patients were smokers than members of the general population
(Scottish Executive Health Department,
1998) (70/101 v. 3183/9047; χ2=49.28,
d.f.=1, P<0.0001).

With regard to fruit and vegetable intake, current smokers compared with
non-smokers were consuming fewer portions per week of fruit and vegetables
(mean=14 (s.d.=12) v. mean=22 (s.d.=19); t=2.73, d.f.=100,
P=0.007).

Body mass index and physical activity

The patients' BMI and waist measurements are shown in
Table 4; 25 (86%) females and
50 (70%) males were either overweight or obese (which is a non-significant
between-gender difference). Two had a BMI of ≥40 kg/m2, that is,
they were morbidly obese. Significantly more female patients than female
controls in the general population were overweight or obese but there was no
difference between male patients and controls; 41 (57%) males and 18 (60%)
females considered themselves to be physically active. They spent a mean of
5.8 (s.d.=5.4) and 6.4 (s.d.=5.2) hours per week, respectively, on physical
activity (which is a non-significant between-gender difference).

Blood measurements

Various blood measurements were carried out to assist in the assessment of
nutritional status and cardiovascular risk (see below)
(Table 5). Where possible,
reference or target ranges are provided. Only two patients had an α
-tocopherol:cholesterol ratio below 2.25, which is considered the
lowest satisfactory value (Panel on
Dietary Reference Values, 1991). However, 64 (74%) patients had a
ratio below 5.00, a value above which it may be desirable to prevent coronary
heart disease (Hense et al,
1993). There were significant correlations between the
cholesterol:HDL ratio and waist measurement (r=0.23,
P=0.03), and the total number of fruit and vegetable portions
consumed and the plasma vitamin C concentration (r=0.28,
P=0.01).

Risk of coronary heart disease and stroke

All necessary blood tests and investigations to make a Framingham
assessment were available for 84 patients. The mean 10-year risk of coronary
heart disease in males was 10.5% (s.d.=8) (compared with the general
population value of 6.4% (s.d.=6); t-test: t=3.33, d.f.=122,
P=0.001) and in females was 7% (s.d.=6) (compared with the general
population value of 4.1% (s.d.=4); t-test: t=1.90, d.f.=42,
P=0.06). The mean 10-year risk for stroke in males was 4.2% (s.d.=4)
(compared with the general population value of 2.3% (s.d.=2); t-test:
t=3.13, d.f.=122, P=0.002) and in females was 3.8% (s.d.=6)
(compared with the general population value of 2.0% (s.d.=3): t-test:
t=1.28, d.f.=42, P=0.21).

There were no significant between-gender differences in the 10-year risk
for coronary heart disease (t-test: t=1.92, d.f.=82,
P=0.06) or for stroke (t=0.37, d.f.=82,
P=0.71).

It has now been suggested (Wood et
al, 1998) that individuals with a coronary heart disease risk
of 30% or higher over 10 years should be treated, for example, with a statin.
Treatment should then move progressively on to those with ≥15% coronary
heart disease risk. In our patients one (1%) female had ≥30% risk of
coronary heart disease and eighteen (28%) males and four (18%) females had a ≥
15% risk.

Mental state assessment and medication

The PANSS scores are shown in Table
6. There were no statistically significant between-gender
differences. With regard to antipsychotic medication the patients were divided
into three groups: those patients receiving long-acting intramuscular typical
antipsychotic medication with or without other antipsychotics (n=27,
27%); those receiving oral typical medication with or without atypicals
(n=22, 22%); and those receiving atypicals alone (n=43,
43%). Six (6%) were receiving no antipsychotic and medication was unknown in
two patients. There were no significant differences in BMI in the three drug
groups. Patients then were divided into those taking only typical medication,
either oral or intramuscular (n=36), and those taking only atypical
medication (n=41). There were no significant between-group
differences in plasma glucose and serum lipid levels or in the BMI.

When the patients were divided into three groups on the basis of fruit and
vegetable consumption, there were no significant differences between those
consuming the most fruit and vegetables (range=19–82 portions per week;
median=29) and those consuming the least (0–7 portions per week;
median=3) in scores on the positive, negative and general psychopathology
sub-scales of the PANSS.

DISCUSSION

Methodological issues

Although almost half of the patients we approached refused to participate
in the study, they did not differ from those who did participate in terms of
gender distribution, age or living arrangements. We have no reason to think
that their diet was very different from that of those who took part. However,
the patients recruited came from a group who were already receiving
considerable professional support in the community. We did not approach those
who were living with well relatives. It is possible that their diets were more
satisfactory.

The dietary questionnaire that we used assesses food intake
retrospectively. It is by no means certain that a prospective weighed intake
of food would have provided a more accurate assessment. However, the
retrospective method offered us the advantage of assessing usual dietary
patterns over a longer time-span. In addition, we did not think that the
patients could cooperate sufficiently in what is a time-consuming and detailed
task.

Dietary habits

Our patients were making poor dietary choices. First, with regard to fruit
and vegetable intake, the average consumption was only 16 portions per week;
the recommended intake is 5 portions per day
(Heimendinger & Van Duyn,
1995). Second, with regard to general aspects of diet, our
patients (and especially the males) were making poorer choices in many more
areas than not only members of the general population in Scotland but also
those in Scotland with the poorest diet, namely those in social class V. A
previous study (Brown et al,
1999) of community-based people with schizophrenia found that no
one was consuming five or more portions of fruit and vegetables a day and that
their diet was higher in fat and lower in fibre than the general
population's.

Why is their diet so poor? There are several possible reasons. First, all
but two patients were unemployed. The diet of the unemployed is probably worse
than that of the employed (Smith,
1985). Second, most of our patients were smokers. In the general
population the diets of smokers, both men and women, are worse than of
non-smokers (Osler et al,
2002); and in the present study we found that, in people with
schizophrenia, smokers had a lower intake of fruit and vegetables than
non-smokers. Third, although we found no difference in mental state scores
between those who had an adequate or low intake of fruit and vegetables,
negative schizophrenic symptoms such as apathy may lead patients to consume
more of the less healthy convenience foods.

Bloods

The majority of our patients had an elevated cholesterol:HDL ratio and a
low α-tocopherol:cholesterol ratio. These observations are likely to be
related to factors such as poor nutrition (increased saturated fat intake),
obesity, lack of exercise and smoking. All of these factors were common in our
patients. However, the number of patients who were folate deficient was very
low (only two individuals). It is possible that the number of patients taking
cereal, which is often supplemented with folate, may explain this finding.

Our patients were found to have serum concentrations of α- and β
-carotene similar to subjects in the lowest quartile for fruit and
vegetable consumption, investigated more than 10 years ago in a study of
British adults (Billson et al,
1999). The various carotenoid concentrations were much lower than
the baseline values in a recently published fruit and vegetable intervention
trial from Oxford (John et al,
2002). The carotenoid results in our patients are indicative of a
diet that contains little in the way of fruit and vegetables, and reflect the
small number of portions of fruit and vegetables that our patients consumed.
Vitamin C, a water-soluble vitamin, is present at plasma concentrations that
appear no different from those recorded in a healthy population recruited from
Oxfordshire in the UK (John et
al, 2002). It is difficult to explain why two such diverse
groups of people with differing fruit and vegetable consumption should have
such similar vitamin C concentrations.

Glucoregulatory and lipid abnormalities have been reported previously to be
more common in patients receiving atypical rather than standard antipsychotics
(Meyer, 2001;
Newcomer et al,
2002). Such differences were not found in the present study.
However, non-fasting blood samples were collected, which may have made it more
difficult to detect differences, and the numbers in each group were small.

Smoking

In addition to having a poor diet, 70% of patients were smokers, which is
twice as many as in the general Scottish population; 54% of those who smoked
were heavy smokers, compared with 11% in the general population in south-west
Scotland (Waldron et al,
1995). The age at which they started smoking was similar to that
of the general population in south-west Scotland
(Waldron et al, 1995)
and was, on average, six years before the first episode of illness. This
finding, reported previously (Kelly &
McCreadie, 1999), emphasises that it is unlikely that the symptoms
of the illness itself lead people to start smoking.

The present study is the baseline for a dietary intervention. Attempts to
help people with schizophrenia to give up smoking should no doubt be tried.
However, so far such attempts have met with little success
(Lavin et al,
1996).

Body mass index

The majority of patients (73%) were overweight or obese. This figure is
higher than in the general Scottish population in 1997 (60%)
(Scottish Executive Health Department,
1998). This may be due in part to lack of physical exercise
because only 59% considered themselves physically active. However, this figure
is very similar to that found in the general population living in a deprived
community in the west of Scotland, where the same questionnaire was used (56%)
(Lowther et al,
2002). Antipsychotic medication is well known to produce weight
gain and only 6% of patients in the present study were not receiving
medication. Smoking usually reduces the BMI. A raised BMI at any age and in
both genders is associated with an increased mortality
(Calle et al, 1999),
but the combination of overweight or obesity with smoking presents a
particularly potent risk for coronary heart disease
(Manson et al,
1990).

Framingham assessment

In view of the patients' eating and smoking habits and their body weight,
it is no surprise that they had a predicted increased risk over the next ten
years of both coronary heart disease (mean 9.6%) and stroke (4.1%); the
difference in risk between male patients and the general population was
statistically significant, and 26% of patients had a 10-year risk of coronary
heart disease ≥15%, a level at which active treatment would be advised
(Wood et al, 1998).
Thus, people with schizophrenia constitute a high-risk group needing priority
for cardiovascular risk reduction. One of the particular hazards of weight
gain (even before reaching the BMI threshold for obesity) is of developing
type 2 diabetes. The proportion of patients in the present study reporting
that they had diabetes was 2%. This is lower than other reports of the current
prevalence of diabetes in people with schizophrenia: 9–14%
(Dixon et al, 2000).
However, there were few female patients in our study; diabetes is twice as
common in females with schizophrenia compared with males
(Dixon et al,
2000).

We conclude that the lifestyle of people with schizophrenia, as measured by
diet, smoking habits, weight and exercise, must give cause for concern in
relation to coronary heart disease. Primary care services should address these
issues. It has been suggested (NHS
Executive, 1999) that general practitioners should be paid for
assessing the physical health of people with severe mental illness and make
any necessary interventions. For this to be successful, practices would need
to be able to identify these patients and develop effective screening
mechanisms (Phelan et al,
2001). In addition, care given from secondary services to people
with schizophrenia in the community, a vulnerable section of the population,
must be concerned also with physical health, otherwise the risk of
cardiovascular and other disease will remain high and patients will die
prematurely. This is the principal reason why we have embarked on a study to
determine whether their diet can be improved, namely through the provision of
free fruit and vegetables. This may be one way in which it is possible to
improve their physical health; other ways might include such things as health
promotion schemes and the prescription of vitamin supplements.

Clinical Implications and Limitations

CLINICAL IMPLICATIONS

The diet of people with schizophrenia is poor; most are smokers and
most are overweight or obese.

People with schizophrenia, especially males, have a predicted
increased risk of both coronary heart disease and stroke.

‘Associative outreach’ from secondary care mental health
services must be concerned not only with mental but also with physical
health.

LIMITATIONS

The patients recruited were already receiving considerable
professional help in the community. We did not approach those living with well
relatives.

Heimendinger, J. & Van Duyn, M. A. S.
(1995) Dietary behaviour change: the challenge of recasting
the role of fruit and vegetables in the American diet. American
Journal of Clinical Nutrition, 61, 1397S
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Panel on Dietary Reference Values of the Committee on Medical
Aspects of Food Policy (1991)Dietary Reference
Values for Food Energy and Nutrients for the United Kingdom.
Department of Health Report on Health and Social Subjects. London:
HMSO.